Prostate cancer is the most commonly diagnosed malignancy in American men and the second leading cause of cancer death in men. Androgen deprivation therapy has been the standard treatment against hormone-dependent prostate cancer; unfortunately, androgen-independent cells usually emerge after a few years of androgen ablation therapy. Chemotherapy is often palliative at this stage, but it does not significantly increase the life span of prostate cancer patients. Because of this situation, many prostate cancer patients turn to alternative therapies to treat their disease, often without informing their physicians. In this proposal, two currently popular herbal preparations, green tea extracts and PC-SPES will be analyzed for their potential to affect the response of prostate cancer at different stages of progression to hormonal interventions, including androgens, anti-androgens, estrogens and inhibitors of 5(alpha)-reductase. In the first aim, it will be determined if green tea extracts and PC-SPES (and extracts of individual component herbs) affect the ability of androgens, anti-androgens and 5(alpha)-reductase inhibitors to control cell cycle processes and the growth of human prostate cancer LNCaP cells representing different stages of prostate cancer progression in culture and as tumor xenografts in athymic nude mice. In the second aim, it will be determined if green tea extracts and PC-SPES (and extracts of individual component herbs) affect the chemotherapeutic effects of epigallocatechin gallate on human prostate LNCaP cancer cells/tumors representing different stages of prostate cancer progression, in culture and in athymic mice. In the third aim, it will be determined if PC-SPES modulates the effects of estrogens and if estrogenic components of PC-SPES are responsible for effects on the cell cycle and the growth of prostate cancer cells representing different stages of prostate cancer progression in culture and in athymic mice.